Evaluation of cancer biomarkers from blood could significantly enable biomarker assessment by providing a relatively non-invasive source of representative tumor material. Circulating Tumor Cells (CTCs) isolated from blood of metastatic cancer patients hold significant promise in this regard.
Punnoose, E. A., Atwal, S. K., Spoerke, J. M., Savage, H., Pandita, A., Yeh, R. F., … Lackner, M. R. (2010). Molecular biomarker analyses using circulating tumor cells. PLoS ONE, 5(9), 1–12. https://doi.org/10.1371/journal.pone.0012517